Within the fields of haptics, there is a general desire to provide tactile stimulus and/or tactile feedback at particular locations and/or at particular regions and/or on so-called tactile displays. Tactile displays have functionality which is distinct from visual or graphic displays, although there is a desire to implement tactile displays and graphic displays on the same devices. Such tactile stimulus may involve one or more of a variety of different types of stimulus and corresponding different sensations, such as, by way of non-limiting example, vibration, changes in pressure, changes in force and/or changes in texture (e.g. roughness, compliance, friction). Methods and apparatus providing tactile stimulus may have a wide variety of applications, including (without limitation): Minimally Invasive Surgery (MIS), sensory substitution, 3D surface generation, games, interactive keyboards, touchpads and/or the like.
Recently, electroactive materials (EAP) have been proposed as potential materials which could be used to implement vibration generators for headphones and smart phone cases and to provide braille cell displays. However, EAP-based devices have drawbacks in that they require: high driving voltage (typically greater than 5 kV) which requires correspondingly complex and expensive driving electronics and proper isolation; and high compliance (typically less than 1 MPa elastic modulus) which makes their vibratory effect difficult to sense. Electro/magnetorheological materials have also been proposed for braille cell displays and texture displays. Tactile stimulus devices using electro/magnetorheological materials require similarly high driving voltages for actuation.
There is a general desire for apparatus and methods for providing human-detectable tactile stimulus and/or feedback. There may be a desire to overcome or ameliorate some of the aforementioned issues or other issues with the prior art.
The foregoing examples of the related art and limitations related thereto are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.